Product transfer vessel



C. EIHULBERT, JR

PRODUCT TRANSFER VES SEL Original Filed June 14. 1965 March 3, 1970 4 Sheets$heet 1 LsL MN CLARHVCE E. HULBERr, JR.

ATTORNEY March 3, 1970 c. E. HULBERT, JR 3,493,003

PRODUCT TRANSFER VESSEL Original Filed June 14, 1965 4 Sheets-Sheet 5 INVENTOR.

CLARENCE E. HULBERZJR.

ATTQRMEY March 3, 1970 c. E. HULBERT, JR 3,493,003

raonvT TRANSFER VESSEL Original Filed June 14. 1965 4 Sheets-Sheet 4 I50 I 1 186 U //36 INVENTOR. 4 CLARENCE E. HULBER-T, JR.

United States Patent U.S. C]. 5112 9 Claims ABSTRACT OF THE DISCLOSURE Apparatus for transferring pulverulent solid materials comprising a first vessel adapted to be subjected alternately to pressure and vacuum and a second vessel adapted to be constantly under pressure, a valve for transfer of material from the first vessel to the second vessel, an inner receptacle in the first vessel, a downwardly extending inlet pipe for transfer of material to the first vessel, an outlet in the top of the inner receptacle, a batfie between the downwardly extending pipe and the outlet, a filter system intermediate the inner receptacle and the wall of the first vessel, means for alternately applying pressure and vacuum to the first vessel, means for opening and closing the valve between the first and second vessel, an eductor for removing material from the second vessel, and a compressor for pressurizing the second vessel.

This application is a division of Ser. No. 463,781, filed June 14, 1965, now abandoned.

This invention pertains generally to automatic cleaning equipment and particularly to equipment and methods which may be utilized in moving products substantial distances while maintaining a velocity of the product at a greater rate than has been heretofore obtained.

Sandblasting is old in the art. Many devices have provided a source of abrasives, passed such abrasives through suitable equipment to increase the velocity of the abrasive, and discharge the abrasive through a nozzle onto a surface to be cleaned. Also, automated cleaning equipment has been limited generally to flat surfaces on substantially small work pieces. Among the expired patents which show various types of abrasive cleaning equipment and methods are the following:

U.S. Patent 1,462,296, Moore et al., issued July 17, 1923.

Patent 1,616,777, Booth, issued Feb. 8, 1927. Patent 1,625,721, Hahn, issued Apr. 19, 1927. Patent 1,635,539, Coleman et al., issued July 12,

Patent 1,858,474, Wolever, issued May 17, 1932. U.S. Patent 2,380,738, Eppler, issued July 31, 1945. U.S. Patent 2,409,722, Stark et al., issued Oct. 22, 1946. Among the prior art patents which have not expired but which indicate various types of cleaning equipment and methods, are the following:

Reissue Patent 23,186, Mead, issued Jan. 3, 1950. U.S. Patent 2,597,434, Bishop et al., issued May 20, 1952.

U.S. Patent 2,570,603, Shoemaker, issued Oct. 9, 1951. U.S. Patent 2,845,091, Neer, issued July 29, 1958. U.S. Patent 3,015,913, Anderson, issued Jan. 9, 1962. U.S. Patent 3,139,705, Histed, issued July 7, 1964. U.S. Patent 3,179,378, Zenz et al., issued Apr. 20, 1965. Thus, it is an object of the present invention to provide improved equipment for cleaning and coating surfaces, particularly the exterior and interior surfaces of products storage tanks.

Yet another object of the present invention is to provide equipment adaptable for sandblasting, such equip- 3,498,003 Patented Mar. 3, 1970 ment being characterized by a vessel which allows continuous and constant movement of abrasive through such equipment.

A still further object of the present invention is to provide cleaning equipment wherein fewer workmen are required.

A further object of the present invention is to provide cleaning apparatus wherein a constant, continuous, and accurate cleaning rate is maintained.

A still further object of the present invention is to provide a sand or dry products pump which may be used to remove sand or dry products from the interior of a ship or other storage device.

Still a further object of the present invention is to provide equipment for conveying products.

Still another object of the present invention is to provide equipment whereby liquids may be conveyed at substantially constant velocity.

A further object of the present invention is to provide abrasive cleaning equipment wherein the air compressor component of such equipment is utilized substantially continuously.

Another object of the present invention is to provide abrasive cleaning equipment characterized by an open hopper storage bin for storing the abrasive.

The equipment of the present invention when utilized for cleaning a surface includes a source of cleaning material such as sand or other abrasives, compressor means, pressure vessel means coupled to said compressor means and to the source of cleaning material, and means coupled to the vessel means for providing continuous flow of abrasives from the vessel means. The vessel means of the present invention include an upper inlet portion which acts both as a high-pressure and low-pressure chamber and a lower portion wherein high-pressure is maintained continuously. Means are provided in the vessel means between the upper chamber and lower chamber to allow sand or other material moving through said vessel to be dropped from the upper chamber to the lower chamber whenever the level in the upper chamber reaches a selected amount. Handle means are also provided on the vessel means to allow material which has accumulated near filters positioned near the outer portion of said vessel means to be dropped into the upper chamber of said vessel means. A moisture bleed is provided near the lower chamber to allow removal of moisture which accumulates in the bottom of the vessel means. An important feature of the vessel means is the movement of abrasive material in said vessel means. Movement of material in the vessel means provides minimum friction loss while allowing maximum use of suction created by blower means coupled to the vessel means. The vessel means further includes a discharge outlet which may be moved to a limited extent to provide constant metered quantity and velocity to the abrasive or other material being discharged from the lower portion of the vessel means. Although the invention has been described briefly with the cleaning operation of a surface, it will be appreciated that the invention allows movement of liquids and solids from storage facilities at a rate heretofore unattainable. The present invention may be utilized, for example, in loading or unloading grain or other materials to or from the hold of a ship, storage bin, or other storage facility where it is difiicult or impossible to locate workmen or to provide equipment which heretofore would satisfactorily perform the required operation.

In the drawings FIGURE 1 is a perspective sketch showing the present invention utilized in cleaning storage tanks;

FIGURE 2 is a combined flow sheet and sketch of the present invention used in cleaning tanks;

FIGURE 3 is a sectional elevational view of the vessel means of the present invention;

FIGURE 4 is a top plan view in section showing the vessel means of the present invention; and

FIGURE 5 is a sectional elevational view taken along line 5-5 of FIGURE 4.

Referring now to the drawings in detail, FIGURE 1 is a perspective sketch showing a typical use of the present invention. A plurality of oil storage tanks 10, 12 and 14 are shown. It will be appreciated that oil storage tanks 10, 12, and 14 are provided with steps A, 12A, and 14A to allow personnel to go from the ground to the top of the tanks. Also, mounds of earth such as 10B, 12B, and 14B surround each one of the respective tanks.

The elevated protective banks 10B, 12B, and 14B surrounding each one of tanks 10, 12 and 14, respectively, act to protect the lower portion of the tanks and to act as an auxiliary storage area in the event liquid leaks from the tanks thereby minimizing fire hazards in the event that tanks 10, 12, and 14 contain combustible liquids. The banks such as 10B, 12B, and 14B present problems, however, when conventional cleaning methods are utilized in cleaning the surfaces 10C, 12C, and 14C of the tanks. Also, steps 10A, 12A, and 14A present a problem in positioning scaffolding and workmen on the exterior of the tanks when such tanks are cleaned by conventional apparatus and conventional methods.

Tank 14 is shown in FIGURE 1 being cleaned by the apparatus of the present invention. A hopper 40 is utilized in storing abrasive material such as sand 42. Hopper 40 may be open as shown to allow abrasives such as sand or other material to be positioned in the hopper. By having an open hopper such as the hopper shown in FIGURE 1, workmen can visibly ascertain when additional material is needed to be placed in the hopper. Also, by having an open hopper there is no necessity for utilizing overhead hoppers or pressurized vessels for storing abrasives or other material in the manner previously utilized in known prior art apparatus. The open hopper allows sand or other abrasives to be positioned in the hopper at any convenient time and in variable quantities, inasmuch as the operation of the storage hopper is not dependent upon any fixed level or amount of abrasive material 42 positioned in such hopper. The portable hopper 40 shown in FIGURE 1 allows easy loading from dump trucks or other rapid loading means.

A suitable conduit such as hose 44 is coupled at 46 to the hopper 40. Hose 44 extends upwardly to the vessel means 50. Vessel means 50 will be explained in detail subsequently. Sufiice it to say for the present however, the vessel means 50 has an intake section 52 where the abrasive 42 enters the vessel means 50.

Coupled to vessel means 50 is a suitable air compressor 20 which mave have, for example, a 1,200 cubic feet per minute capacity. Compressor 20 is coupled through suitable conduits such as hose 22 to a reservoir tank 24. Reservoir tank 24 is coupled to vessel means 50 through suitable pipe means 54 having a two-way remote-operated valve 48. The air compressor provides the pressurized air which is utilized in vessel means 50 in a manner to be explained hereinafter to allow pressurized abrasive 42 to pass through pressure outlet hose 16 to the distributor head and nozzle means 34 positioned on guide tower means 32. Guide tower means 32 is suspended by trolley means 36 from the upper portion of tank 14. An operator 60 is positioned at a suitable location to cause horizontal movement of trolley means 36 and guide tower means 32. Operator 60 further provides vertical movement of the distributor head and nozzle means 34 through a control box 30 coupled through lead 62 to an instrument control box held by operator 60. Lead 64 also comes from the instrument control box panel held by operator 60 and is coupled to trolley means 36 to effectuate horizontal movement of the troll y means 36 to gui e tower means 32,

It will be appreciated that the guide tower means 32 is not rigidly or movably coupled to the earth or to bank 14B surrounding tank 14, but guide tower means 32 and trolley means 36 move around the periphery of :tank 14 without substantial contact at the lower portion of guide tower means 32 with the earth.

Also coupled to vessel means 50 is a blow-down valve 53 and an exhauster or blower 28 which is driven by suitable motive means such as a motor 26. The function and operation of the exhauster or blower 28 will be eX- plained subsequently in connection with the detailed explanation of the interior operation of vessel means 50. A suitable manifold exhaust 29 also is coupled to blower or exhauster 28.

It will be appreciated that the vessel means 50 and associated components may be skid mounted on a suitable plate 70. Such plate or skid 70 may be provided with wheels to allow the vessel means 50 to be easily and efectively moved to desired locations with a minimum amount of effort.

Referring now to FIGURE 2, a combined flow chart and diagrammatic layout is shown in FIGURE 2. Hopper 40 is shown containing abrasive such as sand 42. The abrasive or sand 42 passes through flow line 44 to the intake 52 on vessel means 50. As explained previously, an exhauster or blower 28 is coupled to vessel means 50 through line .128. Reservoir tank 24 is coupled to the upper part of the vessel means 50 through valve 77 in line 76 and valve 74 is coupled to the lower portion of the vessel means 50. Valve 77 is coupled to panel 30 through line 79. The discharge from vessel means 50 passes through line 78 to the distributor head and nozzle means 34 positioned on guide tower means 32. Guide tower means 32 is coupled to trolley means 36 and cable 80 provides vertical movement of the distributor head and nozzle means 34 along guide tower means 32. Cable '80 is coupled to a winch 82 on trolley means 36. Winch 82 may be driven by a pneumatic motor 84 or other suitable power means positioned on the trolley means 36 with pneumatic motor 84 being coupled to valve 88. Valve 88 and valve 98 are coupled through line 86 to air compressor 20 which may be driven by an electric motor 21 or other suitable power means. It will be appreciated that another pneumatic motor 92 is a component of the trolley means 36 and pneumatic motor 92 drives a smaller diameter wheel positioned between wheels 100 and 102 to cause movement of the trolley means 36 around the periphery of tank 14 so that surface 14C is cleaned. Pneumatic motor 92 s coupled through line 96 to valve 98. Pneumatic line 86 is coupled to line 90 to air compressor 20. Pneumatic line 86 is coupled to a manifold in unit 374. Valves 88 and 98 are double-acting electric solenoid-actuated air valves and are operated by line 62 to box 87 which is manually operated by a workman through power source 30 and line 64. Block 31 is a commercial power source or generator coupled through line 33 to panel 30. It is possible to actuate box 87 by suitable signals from a transmitter capable of transmitting an actuating electromagnetic signal. Further it may be noted that limit switches and timer devices may be incorporated on the guide tower means 32 and on the trolley means 36 to actuate the control solenoids 1n unit 374. The selection of manual control or automatic control may be made by selecting a type of operation in box 87.

Line 90 from air compressor 20 is coupled through line to valve 112 and to the reservoir tank 24. Blow-down valve 53 is coupled through line 55 to panel 30. Panel 30 provides an electric source through lead 114 to electric motor 21 and through lead to electric motor 26. Panel 30 provides an electric source through line 203 to control devices 183 and 205 on vessel means 50. Control devices 183 and 205 may be of the type known in the trade as Roto-bin-dicators marketed by The Bindicator Company,

17190 Denver Avenue, Detroit, Mich. and shown in catalog .BDlB-75007-6 1. Blower 28 has coupled thereto exhaust 29 and blower 28 is driven by an electric motor 26 coupled through lead 130 to panel 30.

In viewing FIGURE 2 it will be noted that panel 30, power source 31, box 87, and units 183, 205 and 374 act to provide effective operation of the system of the present invention. As explained previously, air compressor 20 provides air pressure to reservoir tank 24 through valve 112. Valves 53, 77, 88, 98, and 126 may be double-acting electric solenoid air valves or other suitable means such as air controlled valve operators or manually operated valves such as are commercially available to operate effectively with water or other liquids as well as air. Such valves generally are rated at 150 pounds per square inch. The pressure in the upper and lower portions of the vessel means 50 is equalized periodically in a manner to be explained subsequently. Valve 88 controls pneumatic motor 84 which in turn provides rotation to winch 82 thereby causing the distributor head and nozzle means 34 to move vertically because of the coupling to winch 82 through cable 80 past sheave 83. Valve 98 provides actuation to pneumatic motor 92 to cause horizontal movement of the trolley means 34 through rotation of wheels 100 and 102 on tank 14, thereby providing horizontal movement near the tank. Valve 112 is opened upon actuation of the system to allow continuous flow of air from air compressor 20 to reservoir tank 24.

Referring now to FIGURE 3, vessel means 50 of the present invention is shown in sectional elevational form. As explained previously, intake 52 in the upper portion of the vessel means allows products to be brought into the vessel means 50. The products which may be passed into the vessel means 50 may be liquid or solid. The only limitation on the type product which may be passed through the vessel means 50 is the ability of such product to move through a conduit such as pipe. The product brought through inlet 52 passes through a circular chamber such as a pipe 132. Pipe 132 is positioned substantially in the upper portion of the vessel means in order to enter near outer limits of the interior shell of top inner chamber 186. The upper portion of the vessel means includes an outer shell 134 and a cylindrical portion 136. The cylindrical portion 136 has a conical portion 138 coupled thereto. Conical portion 138 is positioned within shell 140 which is substantially the same as many conventional tanks insofar as the external portion of the tank is concerned. Thus, upper portion 142 of the interior tank has a configuration similar to the configuration of upper portion 134 to allow chamber 144 to be provided. Chamber 144 extends downwardly between outer shell 140 and 136 to form chamber 150. A plurality of filters such as filters 146 and 148 shown in FIGURE 3 are positioned in chamber 150 extending around chamber 186. A vacuum pressure relief valve 154 is coupled to the upper portion 134 of the vessel shell and a pressure relief blowdown valve 53 also is coupled to upper portion 134 on the other side of product inlet 52. Inlet 158 is coupled through chamber 160 to provide a suction source. Chamber 160 is a manifold whereby a plurality of filters such as 146 and 148 are attached extending circumferentially around the interior of the exterior wall 136 and interior wall 140 in chamber 150. Doors may be provided in wall 136 to provide access to filters such as 146 and 148 for easy service and replacement of the filters. The filters such as 146 and 148 may be of the perforated cylinder type with filter cloth and screw attachment provided to fasten the filters to manifold 160. The upper inner chamber 186 is a product collecting and metering system and contains a centripetal particle separator. The exterior chamber 150 is a product classifier and injection system. Portions 194, 198 and 202 are openings with portions 198 and 202 coupled to handles 192 and 196 respectively to allow material accumulated in chamber 150 to pass into top inner chamber 186, thus allowing 6 full recovery of product brought into vessel means 50. Inlet 158 is coupled to blower 28 shown in FIGURE 1 and provides suction force for the vessel means 50.

Referring to FIGURE 4, taken along line 44 of FIG- URE 3, baffle 162 is rigidly coupled by members 164 and 166 to shell 140. It will be appreciated that the baffle 162 is solid and shaped as half an open-ended cylinder with curved lip portions 168 and 170 coupled respectively to edge 172 and 174. Product inlet 132 shown in FIGURE 4 is coupled through pipe 178 to an on-olf product intake valve 256 which is coupled at 180 to a valve 77 shown in FIGURE 2 which is coupled to a commercial level-indicating device known as a Bin-dicator as explained previously. The upper Bin-dicator portion is indicated generally as 183 in FIGURE 3 and includes a rotating element 184 and a shaft 182. The upper Bin-dicator 183 indicates when material reaches the level of the rotating vane 184 to stop rotation of such vane thereby indicating that the product has reached the level which has been set by movement of the shaft 182 within chamber 186. Chamber 186 is the product collecting section in the upper portion of the vessel means 50 within tank shell 140. It will be appreciated in viewing FIGURE 4 that chamber 150 extends as a concentric ring or annulus about shell 140 and inside of shell 136.

Thus, when referring to FIGURE 5 taken along line 5-5 of FIGURE 4, it will be apparent that the product entry through intake section 52 moves into chamber 186 as shown with incoming product hitting the product 42 already positioned in chamber 186. Movement of the product is across chamber 186 of FIGURE 5 with a circular, upward movement occurring near bafl'le 162 into chamber 144 between outer shell 134 and shell 142. In

viewing FIGURE 5 it will be noted that inlet 52 is located behind batlle 162 extending into top inner chamber 186 one half the longitudinal axis distance of 162. Opening 171 is located directly on the opposite side of bafile 162 in relation to inlet 52. The phenomena occurring in chamber 186 will be explained subsequently. Filters 188 and 190 are shown positioned in chamber 150. Movement of fine product occurs through chamber 144 downwardly as indicated past filters 188 and 190 as well as other filters extending around the entire periphery of chamber 150 so that fine material 42A accumulates at the juncture of shell 136 and shell 140 which is chamber 150.

Thus, it will be apparent in viewing FIGURE 4 and FIGURE 5 and FIGURE 3 that entry of the product is into chamber 186 with a centripetal movement. The finely ground particles or dust particles are passed upwardly through opening 171 near baffle 162 into chamber 144, filtered by the filter system positioned in chamber 150 and the finely ground or small particles come to rest as shown at 42A in FIGURE 5. When sufiicient particle accumulation has occurred as shown in FIGURE 5, a plurality of doors positioned around shell 140 as shown in FIGURE 3 may be opened to allow movement of the finely ground material into chamber 186. A plurality of handles such as handles 192, 194, and 196, allow movement inwardly as indicated by member 198 on handle 192 and by member 202 on handle 196. Thus, communication is established between chamber 150 into the lower conical portion of the upper part of the vessel means 50 shown in FIGURE 3.

Positioned near the apex of the cone portion 138 is another Bin-dicator or control unit 205 having vane 204 coupled to shaft 206 which extends inwardly to chamber 186. Control unit 205 acts when the top level of product 42 passes below the rotational circle subscribed by the outer part of vane 204 thus indicating that chamber 186 is empty. The control unit 205 operates a microswitch which actuates an electric solenoid air valve in panel 30 through line 203, which air valve in turn actuates valves 126, 77, 53, 212, and 256 to begin a new cycle of filling chamber 186 by putting the upper portion of vessel means 50 under negative pressure by vacuum. Member 212 of valve 213 is actuated by the change in pressure in chamber 186 thus causing upward movement of member 212 into opening 211 to close communication between upper chamber 186 and lower chamber 210. Member 214 is a conical shaped solid material to support the weight of product 42 in chamber 186 thus allowing member 212 to function without restriction because of the weight of product 42 in chamber 186. Conduit or pipe 208 extends into chamber 210 in the lower portion of the vessel means 50 and is in communication with member 21. Member 212 is disposed from member 214 on which product 42 accumulates when there is no communication between chamber 186 and chamber 210. Product 42 moves downwardly along edge 215 of member 214 through opening 216 and opening 211 into chamber 210, which is a high-pressure chamber with respect to chamber 186 in the upper portion of the vessel means 50. Chamber 186 is subject to vacuum or high pressure as the need arises for performing various functions. Product 42 accumulates in the lower portion of chamber 210 and having conical section 220 extending from shell 140 to lower shell 224. Pressure blow down valve 54 is used for relieving pressure in chamber 210 when the entire pressure system is shut down. Thus, a conical chamber 230 is provided at the extreme bottom of vessel means 50 known as a moisture eliminating device. Moisture accumulates in chamber 230 and is bled off through pipe 232 when desired. The outlet from the vessel means 50 is at 234 with a communication conduit extending to product metering valve means 250 positioned in the lower portion of vessel means 50. Valve means 250 will be explained in detail subsequently. Pipe 262 is a continuation of line 208 to provide communication to chamber 230. A communication conduit 252 extends from the valve means 250 to chamber 230 to allow the moisturefree air accumulated in chamber 230 to be discharged through outlet 234.

The suction provided from blower 28 through line 158 of FIGURE 3 goes through chambers 160, 150, 144, and 186 into opening 132 and line 44 of FIGURE 1 thereby producing incoming air through these lines and chambers to blower 28 which allows for the movement of entrained granular or loose products by aeration. Dense or dilute phase pneumatic conveying principles are provided from source 40 to vessel means 50. The relation of air to mass ratios for dry, granular product movement regulates the amount of flow of that product into chamber 186, in direct proportion to size of the line 44, the actual cubic foot per minute displacement of blower 28, the amount of vacuum created in chamber 186, and the velocity created by air movement in line 44 through inlet 132. Inlet 132 should be of an enlarged diameter with respect to line 44 so that the velocity of product entering vessel means 50 is reduced substantially. As an example a three inch diameter line 44 may be used successfully with a six inch diameter inlet 132 to reduce the velocity of the incoming product by four. Abrasive products entering lines 44 and inlet 132 into chamber 186 are moving at high velocities as set forth in Stokes laws and Newtons laws.

The design of the chamber 186 of vessel means 50 takes into consideration the fact that opening 171 must be provided. Considering the fact that the discharge angle from a nozzle decreases along the longitudinal axis as the pressure increases so that increased pressure provides a smaller flare at the tip of the nozzle. As shown in FIGURE 5 the lines 270 and 272 define an angle from opening 171 that provides a reverse effect from that normally encountered when a product leaves a nozzle. By the installation of bafile 162 as shown in FIGURE 5 the inverted conical effect of the cone 271 defined by lines 270 and 272 is partially destroyed. The cone 271 is produced by suction through opening 171. The inlet 132 extends into chamber 186 behind bafile 162 which is positioned between opening 171 and inlet 132. The incoming air and product from inlet 132 seeks an exit through opening 171, the hyperbola described by bafile 162 in cone 271 creates a centripetal separator. The centripetal motion extending from inlet 132 in chamber 186 tends to flow in spiral path thus providing a level product to be formed in chamber 186. Product 42 is brought to rest by striking other particles in product 42 and the energy of incoming product to chamber 186 is dissipated by expansion because of increased volume and because of centripetal motion. Thus accurate measurement of product may be obtained. The distance from opening 171 to the product level control vane 184 is such that the vertical velocity of the air moving through opening 171 allows gravity to act upon the mass of the particles entrained in the air stream. For example, blower 28 producing 300 cubic feet per minute of air exhaust will produce a vacuum of ten inches of mercury and create a velocity of incoming air through a 3 inch line 44 of 6800 feet per minute. The velocity is reduced to 1700 feet per minute in a 6 inch inlet 132 and there is a further reduction in 30 inch diameter chamber 186 to 68 feet per minute. A velocity of 755.5 feet per minute will exist at opening 171 upon entering a 60 inch diameter chamber 144 and the velocity of air will be approximately 15 feet per minute. When considering gravitational force on particles attempting to rise through opening 171 it will be appreciated that such gravitational force is substantially equal to the upward force through opening 171. It will be noted also that fine particles make a ninety degree turn after entry through opening 171 into chamber 144 thereby losing velocity by gravity and then being filtered by a plurality of filters in chamber 150 and falling to the juncture of shell and shell 136 to be injected into chamber 186.

Product captured in chamber 186 allows the control unit 183 to control the quantity captured by actuating valves 126 to a closed position, valve 77 to an open position, valve 53 to an open position, and member 256 to a closed position to stop incoming product when vane 184 does not rotate. Chambers 186, 144, and are then charged to high pressure by line 178 to equalize the high pressure in chamber 210 thus allowing member 212 to open by gravity and by the weight of the product. Product 42 will flow from chamber 186 to chamber 210 in such a rate as the product is being discharged from outlet 234. When product in chamber 186 passes below control unit 205 vane 204 rotates to provide an actuating electrical signal. Valve 77 is closed and valve 53 is opened to relieve pressure in chambers 150, 144, and 186 with member 212 being closed by pressure in chamber 210. By a timing device positioned in panel 30, valve 53 is closed after pressure in chamber 150, 144, and 186 returns to atmospheric pressure. Then valve 126 is opened and member 256 is opened to allow product to again enter chamber 186. The cycle continues automatically to provide a continuous supply of product in chamber 210 to operate under continuous high pressure. A metered uninterrupted flow of product and air mixture continues to flow through line 16 to distributor head and nozzle means 34 for operating upon a surface. The product level in chamber 186 is automatically controlled by the leveling device system to store additional product so chamber 210 is continuously supplied with product.

High pressure chamber 210 is a product totalizer and delivery system. Chamber 210 remains under constant high pressure while the complete system in vessel means 50 is functioning. Product is being moved through outlet 234 at a continuous pressure suitable to move the product substantial distances. The kinetic energy of the product when moved through a hose or other conduit from vessel means 50 encounters less friction loss in such hose or conduit thereby allowing more pressure at the point of discharge of the product at distributor head and nozzle means 34. For example, when the system is made operative, inlet 208 coupled to reservoir tank 24 through valve 74 shown in FIGURE 2 provides pressure to chamber 210. Air simultaneously enters chamber 230 through line 262 of FIGURE 3 and exits through line 252 into product metering valve means 250. Valve means 250 produces a venturi effect at port 281 by the movement of air at high velocity through chamber 308 shown in FIGURE 4. The pressure on the product in chamber 210 and the reduced pressure at port 281 causes the product to flow unrestricted through port 281 into line 266. The product 42 then mixes with the air provided through tapered chamber 308 and the mixture of product and air passes through line 266 and outlet 234. The distance of shoulder 280 on member 268 from line 266 controls the size of port 281 to allow a variable mixture of product and air to be discharged through line 266. It will be noted however that the pressure in line 266 is substantially constant with velocity of product 42 being variable so that the amount of product discharged -at the distributor head and nozzle means 34 will vary according to the positioning of member 294 thereby varying the size of port 281. This feature produces a positive non-clog, constant flow of product.

To shut down vessel means 50, valves 74, 77, and 126 are closed from panel 30, and valves 53 and 54 are opened to relieve pressure in chambers 186, 210, and 230.

The phenomena encountered in the present invention may be termed a reverse-venturic effect to allow rapid filling of chamber 186 with product 42 so that uninterrupted flow of product will occur through vessel means 50.

One of the principal limitations with prior equipment has been the inability to provide constant supply of product at high pressure to supply a constant and continuous portable sandblasting operation for cleaning surfaces. The present invention by utilizing the structure and results obtained in vessel means 50 allow rapid filling of the storage portion of vessel means 50 and measurement of selected quantities to be passed into chamber 210 to assure a continuous and uniform supply of pressurized product to pass through distributor head and nozzle means 34. The vessel means 50 provides means, function, and result heretofore unattainable with other vessel means which handle abrasive materials. Although known vessels have provided high pressure flow and movement of liquids the circulation, movement, and abrading characteristics of abrasive materials has not allowed utilization of such known vessels because improper movement or motion of abrasives within the vessel would cause breakdown, erosion, and deterioration of the vessel shell thickness. Maintaining shell thickness is of primary importance when operating pressure vessels because of safety requirements. It is evident that if a vessel which is processing granular abrasives moving at high velocity within such vessel that the vessel shell will be subject to bombardment by the abrasive thereby causing destruction of the shell of such vessel. In known vessels using cyclone separator principles the circular pattern of the abrasives causes wear on the shell of the vessel. A novel feature of the present invention is the fact that abrasive product fiow enters the vessel means and moves downward to strike upon other abrasive particles rather than upon the vessel shell or vessel components thereby providing .abrasive to abrasive contact instead of abrasive to metal or other material subject to wear. The circular action of the abrasive within vessel means 50 is by centripetal motion rather than by centrifugal motion as in vessels known prior to the present invention. Such known vessels act as a centrifuge instead of the centripetal separator baflle action of the present invention. Therefore the present invention prevents destruction of vessel shells.

The present invention, particularly the vessel means 50, further prevents destruction of the exterior vessel shell by locating chamber 186 so that such chamber is not defined by the outer shell of the vessel means 50 but is positioned in a housing within the outer shell of vessel means 50 thus preventing wear on the outer shell. This feature allows chamber 186 to capture the abrasive entering the top section of vessel means 50 thus providing for complete protection of the filter system and outer shell from damage and wear by abrasion.

The chamber or outer chamber selective product classifier and injection system allows recovery of all fines and dust of the abrasive conveyed into vessel means 50 to be returned without loss of any abrasive whatsoever.

Referring again to FIGURE 4, FIGURE 5 and FIG- URE 3 it will be apparent that movement of abrasives or other products within vessel means 50 is controlled to provide maximium pressure outlet for the metered product upon exit from vessel means 50 while utilizing a compact vessel having optimum baflle positions and optimum chamber shapes. Such vessel means 50 continually supplies product to the distributor head and nozzle means 34 by continuous action, vacuum pressure automatic conveying.

Thus, the present invention provides apparatus for moving products at a high velocity substantial distances so that granular abrasives, for example, may be effectively utilized in the automatic cleaning of work surfaces such as the exterior and interior of large storage tanks such as oil tanks, grain storage tanks, or petrochemicals. The vessel means of the present invention provides effective continuous flow of abrasives through the system so that a uniform anchor pattern is provided on the area being cleaned. In the event that the vessel means is to be utilized merely for product transportation, such transportation can be effected. For example, material in ships and other storage areas may be rapidly and effectively removed with the vessel means of the present invention. The automatic movement of the distributor head and nozzle means of the present invention allows simultaneous movement in both horizontal and vertical directions to obtain any desired path. Thus the present invention provides apparatus which keep pace with recent technological developments in the protective coating industry so that lives, money, and time are saved. Although a preferred embodiment of the present invention has been shown and described in accordance with the statutory mandate of the United States patent laws, the invention is defined by the following claims. Although such claims may be presented in indented format to facilitate reading and understanding thereof, such indented format is not to be construed as a structural or functional limitation of the elements or steps recited in such claims.

What is claimed is:

1. A material transfer vessel comprising:

an outer cylindrical pressure shell having an upper closed end,

a smaller cylindrical inner shell disposed in said outer shell to leave an annular space therebetween, and having its upper end disposed below the upper closed end of the outer shell to leave a space therebetween,

a hopper closing the lower end of said inner shell,

a centrally disposed opening in the upper end of the inner shell providing communication between the interior of the inner shell and the space intermediate the inner shell and the upper closed end of the outer shell,

a vacuum source connected to the space between the inner and outer shells,

a material inlet extending downwardly through the upper end of and into the inner shell, and

a bafile extending downwardly from the upper end of the inner shell intermediate the material inlet and the opening, and extending to below the lower end of the material inlet.

2. A material transfer vessel comprising:

a container,

a material inlet opening downwardly toward the bottom of said container,

an air outlet in an upper portion of said container,

a vacuum source connected to said air outlet,

said air outlet having a substantially larger cross sectional area than the material inlet, so that the 11 velocity through the outlet is substantially less than through the inlet.

3. A material transfer vessel as defined by claim 2,

wherein said air outlet comprises an opening substantially centrally disposed in the top of said container.

4. A material transfer vessel as defined by claim 3,

and including a bafile between said material inlet and said opening.

5. A material transfer vessel as defined by claim 4,

wherein:

said material inlet extends downwardly into said con tainer, and said baflle extends downwardly from the top of said container to below the opening of the material inlet.

6. A material transfer vessel comprising:

a container comprising an outer pressure shell having an upper closed end and a smaller inner shell disposed in said outer shell with an annular space therebetween and a space between the upper end of the inner shell and the upper end of the outer shell,

a material inlet extending downwardly into the inner shell and opening downwardly toward the bottom of the container,

an air outlet substantially centrally disposed in the top of said inner shell,

said air outlet having a substantially larger crosssectional area than the material inlet, so that the velocity therethrough is substantially less,

a vacuum source connected to said air outlet, and

a bafile between said material inlet and said air outlet extending downwardly from the top of said inner shell to below the opening of the material inlet.

7. A material transfer vessel as defined by claim 6,

and including:

filter means-in said annular space intermediate said vacuum source and said air outlet.

8. A material transfer vessel as defined by claim 7,

and including:

a door in the Wall of the inner vessel below said filter means, and means for transferring filtered material from said annular space through said door and into the inner vessel.

9. A material transfer vessel comprising:

an outer pressure shell having an upper closed end,

a smaller cylindrical inner shell disposed in said outer shell to leave an annular space therebetween, and having its upper end disposed below the upper closed end of the outer shell to leave a space therebetween,

a centrally disposed opening in the upper end of the inner shell providing communication between th interior of the inner shell and the space intermediate the inner shell and the upper closed end of the outer shell,

a vacuum source connected to the space between the inner and outer shells,

a material inlet extending downwardly into the inner shell, and

a baffle extending downwardly from the upper end of the inner shell intermediate the material inlet and the opening, and extending to below the lower end of the material inlet.

References Cited UNITED STATES PATENTS 2,521,931 9/1950 Mead 51-12 2,810,991 10/1957 Mead et a1. 51-12 X HAROLD D. WHITEHEAD, Primary Examiner US. Cl. X.R. 302-36 

